Class 12-science

Hello Zala,
Yes, one can study at undergraduate level in Germany. Issue is of finance since not many colleges offer scholarships. However, if you have finance for sustaining at least for four years in Germany please go ahead.

In Gujarat,
Computer Engineering, Mechanical engineering, Electrical engineering and many more engineering courses are available.
Gujarat's famous Colleges for engineering are following:
DIICT ,Gandhinagar
Nirma University ,Ahmedabad
LD College of engineering , Ahmedabad
DDIT, Nadiad
MS University, Vadodara.
Charusat University, Changa

You need to first complete your graduation to be eligible for banking sector.

Hi Ashutosh,
Some popular exams are:
JEE Mains
JEE Advanced
BITSAT
NATA (National Aptitude Test in Architecture)
VITEEE
AIIMS-MBBS
National Defence Academy (NDA) and Naval Academy (NA) Exams

To study in the US you need to do the following: Score very well in academics at school. Register for SAT or ACT. Register for TOEFL iBT, Start researching about the Universities you want to go to. Start working on the university Application via CommonApp. You can also apply to Scholarships like Next Genius Scholarship Program or Tata Scholarship.

Kindly refer to the link mentioned below B.Tech in mechanical engineering colleges:
https://engineering.shiksha.com/be-btech-in-mechanical-engineering-courses-in-mumbai-all-ctpg

Hello Sarika,
For his bright future allow him to follow his interests and let him explore his potential and abilities. Here are some options for a PCM student.
B.E./B.Tech
B.Sc
B.Arch
Defence
Navy
and so on.
If he has a keen interest in other subjects other than engineering then he can check B.Com, BBA, B.Sc-LLB, etc. Find out the psychometric tests online and ask him to take one to know his real aptitude.

It is always advisable to stick to your field. But, as a change for UG with a science background, I would suggest you to pursue BCA and MCA. Otherwise, you can go for B.Com.
All the best.